Nelson-Rigg Waterproof Backpack/Tail Pack - 30L SE-4030100% waterproof, all seams are electronically heat welded Made from durable, UV coated 24oz tarpaulin PVC Watertight roll closure with quick release buckles Bag can seal in two different closure methods, over the top or down the sides Extra large buckle ensures roll stays closed in all environments Air purge valve makes for easy compression Reflective webbing and external bungee storage system Inner sleeve for folders, notebooks, tablets and laptops